Continuous Glucose Monitoring — The First Four Weeks

Abbot Labs Freestyle Libre System

I’ve been using the Abbot Labs Continuous Glucose Monitor for the last four weeks, I’ve seen some massive insights into my lifestyle and overall wellness.

How glucose levels throughout the day compared to activity, heart rate. Whether I’m sitting or moving after a meal. How my body reacts to glucose when I’m sleeping, or when I lack sleep.

What it does when I’m stressed was incredible.

But also, how type 2 diabetes could come about, how maybe it could even be detected years before any official diagnosis.

Using the Glucose Monitor

The monitor comes with a reader and a sensor. The sensor is NFC-powered. It can read through clothes.

The sensor has a needle that goes under the skin, but I don’t even feel it going on.

Sometimes when I roll over on my arm at night, I might feel it, but in general, I don’t even notice it.

Looking at the Data

The device itself gives daily graphs, which are useful. But connecting with a computer and you can get a much better picture of what’s going on.

The default software you get with the Freestyle is not bad. It shows daily trends, individual day charts,

With this, you get averages over the day. Even an estimated HBA1C value that’s accurate (a recent test had it as 34 / 5.3%).

HBA1C levels above 5.7% are considered high-risk for diabetes — Self Hacked goes into it in great detail here.

I haven’t yet been able to export the data directly from the FreeStyle Libre software. But connecting to the third party app Diasend, I could upload and export as a spreadsheet.

Glucose and Meals

This was a huge surprise for me, with some huge spikes in glucose levels after meals.

It wasn’t just the obvious hitting my glucose levels hard — high-carb foods. It was rice (brown and white), sweet potatoes, gluten free bread.

Glucose spiking over ten after eating veg and sweet potatoes.

Functional medicine doctor Chris Kresser talks a good deal about insulin insensitivity, and how post-meal levels above 7.8 are getting into dangerous territory.

The other side of glucose going too high was glucose going too low overnight (hypoglycaemia), caused by very low-carb evening meals.

Glucose and Activity

Walking after a meal stables levels while I’m walking.

Standing desks also help.

I’m getting some of my worst spikes if I’m sitting down after a high-carb meal.

Glucose and Stress

My worst data point by far is when I’ve been most stressed — giving a talk at the Quantified Self Europe conference.

Comparing to Fitbit Heart Rate data. Glucose spikes about 30 minutes after the spike in heart rate.

Sleep impacting glucose control?

I can’t see clear patterns in the data on this yet. I probably don’t have enough clear data points.

Morning Heart Rate Variability measured in the emFit app has an impact. I’m seeing better blood glucose control on days with higher HRV values.

Glucose Impacting Sleep Quality?

When my glucose is low, my sleep is pretty bad. I feel tired after the night, and there are lots of interruptions.

From the emFit, HRV goes down — basically saying I’ve had negative recovery over the night.

Glucose Levels overnight — several dips below 3.
Downward trend in HRV over the night. Heart rate up-and-down over the night also.


From only a few weeks of using the continuous glucose monitor, there are worrying trends in the data — many signs of insulin insensitivity.

But there are also positive signs.

I can see it’s possible to keep blood sugar under control — watching what I eat, sleep well and looking after stress.

Experts in the field say the same thing. Dr. Mark Hyman, a functional medicine doctor, and author talks about insulin sensitivity being reversible.

Diabetes and pre-diabetes ARE reversible by aggressively changing lifestyle, nutritional support, and occasionally medications. — Mark Hyman

Glucose monitors can be a part of that.

I can track how my average glucose and HBA1C levels change over time.

And it holds me accountable. Numbers don’t lie. I can’t fool myself that eating the snacks after lunch is OK.

And I can figure out the small lifestyle adjustments bring the biggest return. What foods are worst for me and what activity works best?

Next Steps

Can I lower my HbA1C levels over the course of the next three months? Measured through the CGM and blood tests. And will lower glucose levels impact any other biomarkers — like cholesterol?

Continuous Glucose Monitor Series

This is the first in a series of posts: